#166AB9
Closest named color: Mid Blue (#276AB3). oklch(52% 0.145 252.2), rgb(22, 106, 185).
Aa
White text reads best on this color (5.53:1).
About this color
#166AB9 is a medium-dark, vivid blue. In OKLCH its lightness is 52%, its chroma 0.145 and its hue 252°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.012 away. White text reads best on it, at 5.53:1.
| Hue family | Blues |
| Lightness | medium-dark (52%) |
| Chroma | vivid (0.145) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 3.79:1 |
| White text | 5.53:1 |
Values
| HEX | #166AB9 |
| RGB | rgb(22, 106, 185) |
| HSL | hsl(209, 79%, 41%) |
| OKLCH | oklch(52% 0.145 252.2) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #166AB9 | 5.53:1 | AA | Lc -82.4 | Fine for body text |
| Black text on #166AB9 | 3.79:1 | AA large text | Lc 27.0 | Dividers and decoration only |
| #166AB9 text on white | 5.53:1 | AA | Lc 77.1 | Fine for body text |
| #166AB9 text on black | 3.79:1 | AA large text | Lc -24.7 | Dividers and decoration only |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 700.
-
Step 50
50
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E0EBF7
oklch(93.5% 0.02 250.4)
-
Step 200
200
#C7DBF3
oklch(88.4% 0.04 253)
-
Step 300
300
#A0C4ED
oklch(80.8% 0.07 252)
-
Step 400
400
#6BA4E5
oklch(70.6% 0.113 252.6)
-
Step 500
500
#408CDD
oklch(63.1% 0.144 252.3)
-
Step 600
600
#1874CB
oklch(55.5% 0.157 252.4)
-
Step 700
700 (this color)
#166AB9
oklch(52% 0.145 252.2)
-
Step 800
800
#0D508E
oklch(42.8% 0.12 252.1)
-
Step 900
900
#154371
oklch(37.7% 0.093 251.7)
-
Step 950
950
#0E2742
oklch(26.9% 0.059 252.4)
#166AB9 with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #4170BC | 0.038 |
| Deuteranopia (no green cones) | #2262B7 | 0.021 |
| Tritanopia (no blue cones) | #007D88 | 0.107 |
| Achromatopsia (no color) | #686868 | 0.145 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #166AB9
#166AB9
oklch(52% 0.145 252.2)
- #905D00
#905D00
oklch(52.2% 0.111 72.3)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #166AB9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.012
- French Blue #436BAD ΔE 0.037
- Windows Blue #3778BF ΔE 0.048
- Flat Blue #3C73A8 ΔE 0.049
- Nice Blue #107AB0 ΔE 0.051
- Ocean Blue #03719C ΔE 0.055
- Muted Blue #3B719F ΔE 0.055
- Peacock Blue #016795 ΔE 0.059
Use #166AB9 in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.